講演情報
[9a-E206-4]Visualization of exciton emission modulation in monolayer WSe2 by standing surface acoustic waves
〇Yuta Takahashi1, Takumi Yamamoto1, Hidetoshi Kanzawa1, Kazuki Maezawa1, Hajime Kumazaki1, Shinichi Watanabe1, Shun Fujii1 (1.Keio Univ.)
キーワード：
Transition metal dichalcogenides、Excitons、Surface acoustic waves
Monolayer transition metal dichalcogenides exhibit strong excitonic photoluminescence even at room temperature, making them promising platforms for exciton control. While Rayleigh-type surface acoustic waves (RSAWs) can modulate excitons through both strain and piezoelectric fields, these effects are difficult to distinguish because they coexist spatially and temporally. Here, standing surface acoustic waves (SSAWs) are applied to monolayer WSe2 on 128° Y-cut LiNbO3 to spatially separate these effects: strain is localized near antinodes, whereas in-plane piezoelectric fields are localized near nodes. Using stroboscopic PL spectroscopy synchronized with the SSAW phase and simultaneous Michelson interferometry, PL spectra are measured over one acoustic cycle at nodes and antinodes. At nodes, PL intensity decreases during half of the cycle without energy modulation, indicating exciton dissociation by the in-plane piezoelectric field. At antinodes, PL energy and intensity oscillate with the SSAW period, showing strain-dominated modulation. These results demonstrate spatially resolved separation of piezoelectric-field- and strain-induced exciton modulation in monolayer WSe2.